Most computer users in the desktop environment employ some sort of data protection procedures and devices to protect computer system files and data files in the event of an accidental delete or overwrite of these files from the primary storage medium, which is usually the computer's hard drive. Computer data protection systems usually involve the backup of system and data files onto some sort of secondary storage device utilizing removable storage media, such as floppy disk drives, other hard disk drives, tape drives, etc. More sophisticated users may utilize automatic data protection devices and procedures that backup the entire system on a regular basis, allowing for a full system recovery if needed.
For example, tape backup systems are used to protect data files and other information from computer system failures such as hard disk crashes or computer virus attacks. A tape backup system stores this data on removable off-line media (i.e., the tape); this data can then be retrieved in the event of data loss. Conventional backup systems typically provide the end user with a choice of making a “full” backup or an “intermediate” or “modified” backup. Full backups make complete copies of all the data on the computer to a set of one or more backup tapes. Incremental backups are generally much smaller than full backups since they simply save the data that has been changed since either the last full backup or the most recent incremental backup. Example of such prior art backup systems are described in U.S. Pat. No. 5,276,860, U.S. Pat. No. 5,758,067, U.S. Pat. No. 6,212,512, and U.S. Pat. No. 6,330,570.
Further, a backup system for Enterprise Data Protection and Disaster Recovery is commercially available from Hewlett Packard, i.e. HP OpenView Storage Data Protector.